A known problem of material mining, such as rock or coal mining, is the high amounts of particulates produced during mining. These particulates are often abrasive and may cause wear to mining components which are exposed to these particulates, such as a drive unit for a chain scraper conveyor or a plough chain conveyor. Such a drive unit typically includes a bearing housing accommodating a bearing for supporting a drive shaft of the drive unit. The drive unit further includes a sprocket drivably connected to the drive shaft and configured to drive a conveyor chain of the chain conveyor. A narrow gap between the bearing housing and the sprocket—usually referred to as a seal gap—enables the sprocket to rotate freely relative to the bearing housing. Particulates produced during mining may enter that seal gap, get trapped and eventually clog up the seal gap. As a result, the bearing may be subjected to material wear which may result in a reduced lifetime or even failure of this component.
Various seal arrangements for rotary bearing devices are known, for example, from U.S. Pat. Nos. 2,395,147 A, 8,245,837 B2, 1,163,045 A, 3,545,582 A, 3,476,396 A, 4,913,279 A, JP 2009287785 A and JP 2010196830 A. The latter, for example, shows a roller bearing device for improving a seal function by adding a structure for removing foreign matter.
Sprockets used in drive units are known, for example, from U.S. Pat. Nos. 4,346,938 A, 3,946,859 A.
The present disclosure is directed, at least in part, to improving or overcoming one or more aspects of prior systems.